<!DOCTYPE html>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
  <title> 基础盒模型 </title>
  <style type="text/css">
    div,span {
      width: 300px;
      height: 40px;
      border: 1px solid black;
    }

    body>div {
      display:inline;
    }

    /* 将span元素改为block盒模型 */
    body>span {
      display:block;
    }
  </style>
</head>

<body>
  <div>div元素一</div>
  <div>div元素二</div>
  <span>span元素一</span>
  <span>span元素二</span>
</body>
</html>
